Well did you check if your dns server is working properly on the local host as "NXDOMAIN" in your dig output indicates, that it did not find anything.

Regarding the ouput from the internet, did you check if the dns service is reachable from outside? (Firewall / ACL of bind blocking the access, bind listening on the localhost interface, only, check with netstat -tap)

So, bind is up and running.
If I look at /etc/bind there are all files, zone files and so on.
If I create a new zone at ISPConfig the zone file will also created at the /etc/bind directory.
The named.conf.local file contains all zones which are activated at ISPConfig